Investigating how particular genetic factors, environmental influences and gene-environment interactions are mediated and gain phenotypic expression in visually guided behaviors is the purpose of this project. Its method is first to relate variations of visual approach-preferences in newly hatched and visually naive quail chicks (C. coturnix japonica) to variations of genotypes, and then to trace interactions of particular genetic influences and environmental input in the short and long-term processes of early and early to adult developments of visually guided behaviors. The point of departure is a bidirectional genetic selection study of the quail's early color preferences, which has now reached the 16th generation. This study has provided data implicating relatively simple Mendelian mechanisms of inheritance. Ongoing research concentrates on overt phenotypic expression and covert mediation of such gene effects, plus environmental effects and gene-environment interactions. Data are anticipated to reflect on the ways the vertebrate brain processes visual information; and the project to contribute to resolution of the nature-nurture issue relating to behavior and behavioral development.